1. Field of the Invention
The invention relates to an outer ring of a tapered roller bearing, and a tapered roller bearing.
2. Description of Related Art
Japanese Patent Application Publication No. 11-48805 describes a conventional tapered roller bearing. This tapered roller bearing is provided in a differential gear unit, and supports a pinion shaft such that the pinion shaft is rotatable relative to a housing of the differential gear unit.
The tapered roller bearing described above includes an outer ring, an inner ring, and a plurality of tapered rollers. The outer peripheral face of the outer ring is fixedly fitted onto the inner peripheral face of the housing. The inner peripheral face of the inner ring is fixedly fitted onto the outer peripheral face of the pinion shaft. The tapered rollers are arranged at given intervals in the circumferential direction, between the tapered raceway surface of the outer ring and the tapered raceway surface of the inner ring. The tapered rollers are retained by a cage. The outer ring of the tapered roller bearing described above is solid.
However, weight reduction of the conventional tapered roller bearing described above is difficult because the outer ring is solid. If this tapered roller bearing is used in a vehicle, its large weight results in a higher operating cost and a higher material cost.
In addition, because the outer ring of the conventional tapered roller bearing described above is solid, the outer ring requires a large amount of machining, making the machining work more time-consuming. That is, the manufacturing cost of such an outer ring is high, which is not desirable.